Servos stop moving intermittantly- Update...
10-13-2003, 07:42 PM
#26
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RE: Servos stop moving intermittantly- Update...
I lost my back up PW Extra to this problem.
From what I found out is that it seems to be limited to Futaba receivers.
TO make a long story short. on a 6 volt pack, the power voltage may be 6 volts but the control voltage may be as low as 3.3 volts. Futaba seems to put out the lowest control voltage of all the receiver brands. I found that out of 6 extensions (all HD) 2 failed out right. 2 worked, and 1 (one on the plane) was intermittent. I have 36" extensions connected directly to the servo amp board and now the problem is gone.
From what I found out is that it seems to be limited to Futaba receivers.
TO make a long story short. on a 6 volt pack, the power voltage may be 6 volts but the control voltage may be as low as 3.3 volts. Futaba seems to put out the lowest control voltage of all the receiver brands. I found that out of 6 extensions (all HD) 2 failed out right. 2 worked, and 1 (one on the plane) was intermittent. I have 36" extensions connected directly to the servo amp board and now the problem is gone.
ORIGINAL: MHawker-RCU
I have a 25% Extra with a Hitec 5625 Digital servos in the ailerons. Everything has been fine for about 20 -30 flights or so (about 6 months).
This last weekend while doing a range check etc, I noticed the aileron servos stopped working intermittantly while wiggling the stick quickly back and forth. Long story short, one or the other or both would stop. I have them on separate channels of a 149DP RX (see further in the story before thinking it's a PCM thing). And, so far, only the ailerons are affected, although I thought one of the elevators (separate channels too) stopped once.
I originally thought it was the battery. I charged it at the field to make sure it was fully charged. It read 5.3v on a loaded meter. Same thing. I scrapped the flight for that day.
At home I tried another battery (fully charged NiCd pack), another RX, other servos and finally narrowed it down to the servo extensions. I went to the LHS and got another set of Hitec HD extensions. The 24" ext would still cause the same problem and the 12" would not. BUT, some 605bb's that I had laying around would work fine with any extension.
Sooooooo, since I know people have been using longer extensions (including me) with digital servos, why do you think it's the servos? I understand that digi's use more power, but something doesn't make sense. Oh, they have a Mar 02 stamp on them.
Any ideas would be appreciated.
I have a 25% Extra with a Hitec 5625 Digital servos in the ailerons. Everything has been fine for about 20 -30 flights or so (about 6 months).
This last weekend while doing a range check etc, I noticed the aileron servos stopped working intermittantly while wiggling the stick quickly back and forth. Long story short, one or the other or both would stop. I have them on separate channels of a 149DP RX (see further in the story before thinking it's a PCM thing). And, so far, only the ailerons are affected, although I thought one of the elevators (separate channels too) stopped once.
I originally thought it was the battery. I charged it at the field to make sure it was fully charged. It read 5.3v on a loaded meter. Same thing. I scrapped the flight for that day.
At home I tried another battery (fully charged NiCd pack), another RX, other servos and finally narrowed it down to the servo extensions. I went to the LHS and got another set of Hitec HD extensions. The 24" ext would still cause the same problem and the 12" would not. BUT, some 605bb's that I had laying around would work fine with any extension.
Sooooooo, since I know people have been using longer extensions (including me) with digital servos, why do you think it's the servos? I understand that digi's use more power, but something doesn't make sense. Oh, they have a Mar 02 stamp on them.
Any ideas would be appreciated.
10-14-2003, 11:10 AM
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RE: Servos stop moving intermittantly- Update...
Thanks for the thoughts, Geistware, and sorry you lost a plane. I did try a Hitec Electron 6 RX which exhibited the same problem. It was the RX that was in it when I brought it in to Hitec. You are right about the 3v deal with the RX. Steve at Hitec told me the same thing, but he seemed to suggest it was that way with all RX's. I didn't really get into the details about it with him though.
I wonder if it was just two bad extensions afterall?
Re: your servo amp board... could you point me to how that is designed?
I wonder if it was just two bad extensions afterall?
Re: your servo amp board... could you point me to how that is designed?
